1. Synopsis of my work experience Prajwal Nimmagadda Graduate Research Assistant Dept of Mechanical Engg University of North Carolina at Charlotte
2. Overview About me My individual projects since 2003 Undergrad intern project Undergrad final year project Work at Industry, in India Research Work at UNC Charlotte,NC USA August 2006
3. Who am I ? Master’s Research Student at the University of North Carolina at Charlotte Majoring in Mechanical Engineering (GPA:3.43) Design and Analysis Worked on Pro-E and ANSYS also on MSC Nastran from August 2004 Theoretical and working knowledge of Finite Element Methods/Analysis Current Research Haptic Feedback control: Haptic feedback system to reduce the probability of rollover in a heavy truck through induced steering wheel vibrations
4. Undergraduate intern project Developed a repositioning mechanism for a toppled hexapod (a six legged robot) Involved use of rack and pinion mechanism on either ends to do the repositioning Making 180o, to and fro motion from a 360o rotating motor using linkage mechanisms. Used C to achieve this motion and simulated it in C
5. Undergraduate final year project STRUCTURAL ANALYSIS OF TRUCK CHASSIS FRAME USING FINITE ELEMENT ANALYSIS Problem Definition : To perform structural analysis on a parametrically defined model of a truck frame, optimize the critical parameters. Import to IGES format for exporting to MSC Patran Imported to MSC Patran Original 2-D drawings of truck chassis 3-D drawings and Assembly in Pro-E Data Loss (missing surfaces) reconstructed in Patran Meshing using Quad 4 elements and TRIA elements (Shell Elements) Grouping of surfaces with similar thicknesses Removal of holes reduces the stress concentration in regions of the frame Applying Multi Point Constraints (to simulate the presence of Bolts) Application of Loads and Boundary conditions Solving using Nastran (Solver) Post –Processing and Result analysis
6. Work at Industry TASK I During the first month of the stay, I assisted a PhD student from The University of Malaysia, Sabah on “Simulation of Piezo-Resistive Metal Gauge on Rectangular Membrane for Low Pressure Application”. I was given a problem of a stress state on a thin membrane. This required me to create a membrane of the order of a few microns and the membrane consisted of multiple layers of different materials. And on top of the membrane was a resistance strain gage which was again of much lesser dimension compared to the original membrane. This resistance strain gage was made of another material. So, eventually there were more than 2 materials involved. The relative motion (sliding) between the gage and the membrane needed to be stopped by gluing them together, as the gage was placed to check the strain in the membrane. Then the low pressure that needed to be applied was applied on the top surface of the membrane which consisted of the resistance gage. The strain developed in the gage was compared with the strain on the membrane. And the results were given to the PhD scholar.
8. Task II(Modal Analysis of Turret of a Battle Tank using Finite Element Analysis) Gun positioning accuracy is very much dependent on turret structure and its stiffness Solid Model Turret Gun Barrel Finite Element Model Number of Elements in Gun Barrel = 74000 Number of Elements in Gun Barrel = 175000 Number of Elements in Turret = 94000 Element Type = Structural Solid Tetrahedral
